<!DOCTYPE html>  
<html>  
<head>  
<meta charset="utf-8"/>  
<title>异步加载</title>  
<script type="text/javascript">  
function initialize() {  
  var mp = new BMap.Map('map');  
  mp.centerAndZoom(new BMap.Point(121.491, 31.233), 11);  
}  
   
function loadScript() {  
  var script = document.createElement("script");  
  script.src = "http://api.map.baidu.com/api?v=2.0&ak=2wLir4fArFb8LO6cTAscK5MH9ifkcC2U&callback=initialize";//此为v2.0版本的引用方式  
  // http://api.map.baidu.com/api?v=1.4&ak=您的密钥&callback=initialize"; //此为v1.4版本及以前版本的引用方式  
  document.body.appendChild(script);  
}  
   
window.onload = loadScript;  
</script>  
</head>  
<body>  
  <div id="map" style="width:500px;height:320px"></div>  
</body>  
</html>
